Level of believability: Roughly the same as the rumor that Keanu Reeves married David Geffen.

Evidence for: In da Vinci's Last Supper, the images of Jesus and the would-be Mary appear to form an M, supposedly standing for marriage or matrimony. According to some interpretations, the Gospel of Philip has Jesus kissing Mary on the mouth and favoring her over his disciples.

Evidence against: There is no known credible written record suggesting that either of them ever married.

Number of Hail Marys Dan Brown should say for this one: 3,300, roughly the same as if he ate meat on Friday during Lent — at the gay wedding of two stem-cell researchers.

CLAIM: Jesus and Mary Magdalene had a child together named Sarah, beginning a new royal bloodline.

Level of sacrilegiousness: 5 pitchforks

Level of believability: 100 percent, according to Tom Cruise's publicist.

Evidence for: The Gospel of Matthew mentions a holy family that was forced to flee to Egypt, which could be a reference to Mary and her child.

Evidence against: There's no credible written record anywhere to support the claim.

Number of Hail Marys Dan Brown should say for this one: 112,358. How do you like the Fibonacci sequence now, bitch?

CLAIM: Leonardo da Vinci was a flamboyant homosexual.

Level of sacrilegiousness: 1 pitchfork

Level of believability: High. The Renaissance was the Bravo network of historical eras.

Evidence for: He painted several homoerotic pieces and was accused of sodomy with a seventeen-year-old boy.

Evidence against: Way too into helicopters, tanks, and other nongrooming gadgets.

Number of Hail Marys Dan Brown should say for this one: None. Look, it's not as if anyone's trying to cover anything up here...

CLAIM: The person to Jesus' right in The Last Supper is actually Mary Magdalene.

Level of sacrilegiousness: 3.5 pitchforks

Level of believability: If an old grilled-cheese sandwich with an image of the Virgin Mary on it can fetch twenty-eight grand on eBay, anything's possible.

Evidence for: The figure wears garments with inverse colors to those of Jesus and appears to have a bosom.

Evidence against: Some art historians argue that the figure is wearing men's garments. The inclusion of Mary would mean that John is missing.

Number of Hail Marys Dan Brown should say for this one: 12, and be forced to watch Mona Lisa Smile with the director's commentary.

CLAIM: Opus Dei is a highly organized, monastic Catholic cult dedicated to keeping the Jesus-Mary secret from being revealed.

Level of sacrilegiousness: 3 pitchforks

Level of believability: Fairly low. It's a real sect, but its members are probably far more concerned about what's in ninth-grade-biology textbooks.

Evidence for: It is influential in church politics, and ex-members have made claims about corporal mortification and other practices consistent with those depicted in The Da Vinci Code.

Evidence against: Opus Dei wasn't founded until 1928, for reasons seemingly unrelated to the Jesus-Mary connection. It has made a great deal of information about its mission, belief system, and activities available to the public, and the majority of its members are laypeople.

Number of Hail Marys Dan Brown should say for this one: 456 — while Oprah Winfrey tears him a new one for fabricating.